package cn.chencq.collection.array;

import java.math.BigInteger;
import java.util.Scanner;

public class TestB {
	public static void main(String[] args) {
		System.out.println("please input a int value:");
		Scanner in = new Scanner(System.in);
		int value = in.nextInt();
		BigInteger result = BigInteger.valueOf(1);
		for (int i = 1; i <= value; i++) {
			result = result.multiply(BigInteger.valueOf(i));

		}
		System.out.println(result);
	}

}
